The present invention relates to modular supplies and more particularly to a novel and unique power supply organization providing a number of significant features under common control of a pre-programmed microprocessor.
The utilization of power supplies in modern technology requires precise levels of control as well as accurate monitoring and adequacy of safety features. In addition, power supplies should be easy to use as well as having features which increase the flexibility and utility of such systems.
In particular applications where groups of individual power supplies, all under common control, are required, and especially where high power requirements are needed in conjunction with both AC and DC supplies, prior art systems have been lacking in the capability to fully integrate, monitor and control supplies exhibiting such features. More particularly, in areas requiring multiple sources, and wherein high power must be supplied to a plurality of areas, safety features should be of paramount importance. Thus design integration of an accurate, controllable multiple supply system, including the use of common controllers and safety interlocks, is desirable.
It is therefore the principal object of the present invention to provide a modular power supply, capable of providing multiplicities of power outputs, which may be easily adjusted by the user, and which may be monitored and controlled for accuracy in accordance with the desired values.
An example wherein multiplicities of individual supplies may be utilized under common control is in the implementation of a multi-electrode device, such as an ion source. In a device of this type, several diverse supplies of both AC and DC nature are required. In addition, some of the supplies may be interrelated, and all of the energy output should be either key-enterable or otherwise changed in accordance with various energy settings which may be applied to the various filaments and electrodes of such a device. Prior art devices normally utilize heavy inductive elements, large scale power transformers, and effect variation in output conditions by means of Variacs of other similar large scale power control devices. These devices are not only inefficient, but require large amounts of space as well as cooling capacity. In addition, each of the supplies is conventionally unrelated, each being controlled by means of the operator simply setting the values of each supply in accordance with desired outputs. In addition to the lack of an ability to effect common control over a multiplicity of supplies in such conventional technology, the use of previous switch mode power supplies has created additional problems with respect to high voltage levels which make such supplies difficult to use. Finally, the inability to provide adequate safety interlocks in the system wherein pluralities of power supplies are necessarily employed is a further disadvantage inherent in such systems.
It is a further object of the invention to provide a power supply employing modular units which may each be removed and replaced, and further provided with an interlock system which prevents high power from being present in the open areas of such a modular system when any individual unit is removed.
It is another object of the present invention to provide a common controller for a multiplicity of power supplies which provides for scanning of control and insertion of new value, as well as monitoring external conditions to determine if interrupts or power supply shut downs should be initiated.
It is a still further object of the present invention to provide a switching power supply wherein more efficient utilization of the duty cycle of the pulses employed in such supply eliminates the need for excessive size of inductive elements.
It is another object of the present invention to provide an improved feedback control system for more accurately effecting control of output conditions.
It is a further object of the present invention to improve accuracy of measured values in a power supply by automatically calibrating for component errors at start-up conditions.